Having lived through a disaster with 30,000 people evacuating it opened my eyes to the fallacies of most "disaster plans".
1. ALWAYS having enough gas in the car to travel 100 + miles away from the danger zone. Local power and cell towers are frequently gone. No power for ATMs, gas pumps, water pumps, TVs, cash registers, grocery stores, internet, etc. A few hundred dollars CASH in small bills can really help. There will be few places to stay nearby if thousands of people are displaced. I was surprised at how quickly the criminal element gathered their friends and weapons and started patrolling closed areas looking for easy targets to loot. Distance is your friend.